Scientists eager to begin studies on human stem cells got some good news today. The National Institutes of Health (NIH) announced that, contrary to what many had feared, U.S. law does not bar federal support for this burgeoning field. Stem cells have the potential to develop into a wide variety of human tissues; researchers hope to use them for studies ranging from basic research on early human development to new technologies for tissue transplantation.

When researchers first announced in November that they had derived so-called stem cell lines from human embryo and fetal tissue (Science, 6 November 1998, p. 1014[2]), NIH officials were concerned that federal law might restrict the use of the cells to private labs. For example, a clause added to the 1999 NIH appropriation bill makes it unlawful to spend federal funds on the creation of embryos "for research purposes," and it blocks support of research in which embryos are "destroyed, discarded or knowingly subjected to risk of injury or death. ..."

At a meeting today of the National Bioethics Advisory Commission (NBAC) in Washington, D.C., however, NIH director Harold Varmus released a memo on stem cell research by Harriet Rabb, general counsel of the Department of Health and Human Services, making it clear that there is no legal reason why funding of stem cell research cannot begin now. Rabb argues that although the law would prohibit the development of cell lines from embryos (both stem cell lines announced in November were developed with private funds), it does not apply to the use of the cells. Stem cells are not organisms--or even precursor organisms, in her view--for they cannot develop into an embryo even if implanted in a woman's uterus.

After hearing from NBAC, researchers, and the public, Varmus hopes to draw up "clear guidelines" by midyear describing what can and cannot be done under the law. Grant money could be approved as early as this fall, according to NIH staffers. "I am delighted to hear NIH made this decision," said Senator Arlen Specter (R-PA), chair of the subcommittee that approves NIH's appropriation bill, noting that it does not violate congressional intent. Specter supports the decision, he added, because stem cell research holds out promise for "enormous advances in Parkinson's, Alzheimer's, diabetes, and heart disease."